[gsg]

"Race to sleep" is a well known power saving strategy.

> This of course ignores leakage

You can't ignore leakage. The ability of a chip to turn off currently unused silicon is crucial to power management on modern devices.

[loup-vaillant]

Of course you can't. But if leakage consume 25% of CPU power, then halving the frequency is still worth it. Leakage may be important, but that doesn't mean it dominates.

Now if as an app developer you have zero control over the CPU frequency, sure, the best strategy is probably to write your code to be as fast as possible. But if you're really big on battery life, someone will have control over CPU clocking or voltage. In which case race to sleep is no longer the only viable strategy.